Study On Foam Stability And Defoaming Behavior Of Fine Hematite Concentrate

In order to solve the influence of excessively stable flotation concentrate foam on settling,filtration and other technological processes,The effects of the concentration of sodium oleate,p H,temperature and hematite size on the foam stability under different conditions were investigated by foam stability test.As well,the best defoaming method was explored by mechanical stirring,heating and adding defoaming agent.At the same time,the corresponding mechanism was studied and analyzed.The foam stability test showed that the stability increased firstly and then decreased with the increase of the dosage of sodium oleate,When the dosage of sodium oleate was 1×10-3mol/L,the foam stability was the strongest.The effect of temperature shows different under different dosage of sodium oleate.Strong acid and alkaline are not conducive to the formation and stability of foam,as well the effect of p H is also different under different dosage of sodium oleate.The stability of three-phase foam is affected by hematite particle size and pulp concentration greatly.Foam stability is very poor under coarse grain condition;as well,under the condition of fine particle size,the stability of three-phase foam decreases firstly and then increases greatly with the increase of pulp concentration,and the finer the particle size is,the stronger the foam stability will be.The defoaming test showed that the defoaming effect of organosilicone and dimethyl silicone oil on two-phase foam was very significant,but the effect of tributyl phosphate was poor.For three-phase foam,it is difficult for the defoaming agent to diffuse to the liquid film surface under the state of standing,so the defoaming effect of the three defoaming agents is very poor.Under the condition of stirring at a low speed about 200r/min,the defoaming ability was significantly enhanced with the use of defoaming agent,and the stability of three-phase foam was greatly reduced.Mechanism studies show that there is a certain relationship between foam stability and solution surface tension and foam viscosity,as well low surface tensionand high viscosity are the foundation of forming stable foam.The defoaming agent can change the surface tension of the solution to some extent,but it is mainly by reducing the viscosity of the foam to enhance the drainage process of the liquid film,so as to reduce the stability of the foam and achieve defoaming.